This invention relates generally to the field of surgical devices, and more specifically to a resectoscope.
A resectoscope is employed transurethrally to perform prostate and/or bladder surgery. This device has an elongate section provided with an outer sheath, generally made of stainless steel, which is inserted into the urethra. The outer sheath prevents the urethra from contracting, while working elements internally of the sheath are employed to cut away the desired tissue.
Conventional resectoscopes either are of the cold punch type, wherein the cutting element is unheated, or are of the heated type, wherein a cutting element, in the form of a conductive wire, is heated through an electrical connection to a diathermy unit. The diathermy unit can be controlled by the surgeon, either through the use of a hand-operated switch, or through the use of a foot-operated switch.
In a manually operated resectoscope of the type employing a heated cutting element the surgeon manually extends the cutting element beyond the end of the outer sheath to a position engaging the tissue to be cut. Thereafter, the cutting element is energized through actuation of the diathermy unit, and at the same time the cutting element is manually retracted to cause it to slice away a desired chunk of the tissue. The surgeon views the area being operated upon through a telescopic system that also is mounted within the stainless steel sheath of the device, and a continuous irrigation system is utilized to keep the line-of-sight free of blood and other debris.
During prostate surgery it is common to cut away approximately 1/10 of a gram of tissue with each cutting stroke of the resectoscope. Although the total weight of tissue to be removed varies with the size of the individual and the severity of the problem, it is quite common to remove anywhere from 20 to 150 grams of tissue in a typical prostate operation. Therefore, in even the simplest of operations, it is generally necessary to reciprocate the cutting element at least 200 times.
In a convention manual resectoscope this will require the surgeon to manually extend the cutting element outwardly of the protective sheath, and then manually retract the element through its tissue-cutting stroke, while at the same time applying heat to the cutting element by the manual actuation of the diathermy unit. Obviously, carrying out these manual steps 600 or more times in a single operation is a time consuming and tiring procedure.
Although it may be desirable during various phases of the surgical procedure to manually control the reciprocation and heating of the cutting element of the resectoscope, other phases of the procedure, and in many cases the entire surgical procedure, could be carried out by an automatic system, wherein the cutting element is automatically reciprocated at a desired cutting frequency under control of a separate power source. To the best of applicant's knowledge there are no presently existing resectoscopes which are capable of both manual and automatic operation. In other words, the prior art resectoscopes are either designed to be manually operated or automatically operated. However, there is no single resectoscope which can be adapted for either automatic or manual operation.
Moreover, although there are teachings in the prior art of automatically operated resectoscopes, they either are of the cold-punch type, wherein the cutting element is not heated, or the cutting element is constantly heated during all portions of its reciprocating stroke. In other words, applicant is not aware of any prior art resectoscopes in which the cutting element is automatically reciprocated, but only selectively heated during the cutting part of the reciprocating stroke.
Canadian Pat. No. 452,125, issued to Wallace, discloses a resectoscope employing a motor (not shown) which is controlled by a switch to automatically reciprocate a cutting element. The switch also functions to complete the heating circuit, whereby the cutting tip will be constantly heated while it is being reciprocated. In other words, the Wallace device does not provide any arrangement for intermittently applying current to the cutting tip, let alone intermittently applying the current to the tip in a timed relationship with the cutting stroke. Moreover, it should be noted that the device disclosed in the Wallace Canadian patent is not capable of being converted from automatic to manual operation. In other words, the device either operates automatically under the control of the motor, or it does not operate at all.
U.S. Pat. No. 2,545,865, also issued to Wallace, discloses a resectoscope which can be operated with one hand to both reciprocate the cutting element and control electrical energization of the cutting tip. This is representative of the prior art type of devices where reciprocation of the cutting tip only is carried out manually.
U.S. Pat. No. 3,149,633, issued to Zingale relates to a resectoscope wherein the tip is reciprocated by a pneumatic control system. In the Zingale device the cutting tip is not automatically reciprocated at a predetermined frequency. Instead, the exact position of the cutting tip is determined by the degree of depression of an actuating button 102. Thus, reciprocation of the cutting tip is achieved by sequentially depressing and releasing the button 102 to provide a manual mode of operation. Moreover, in the Zingale device the heating of the tip is not timed with the reciprocating motion. Rather, a separate foot control system is employed by the surgeon to manually energize the tip.
U.S. Pat. No. 4,196,734, issued to Harris, discloses a control system which can be used to apply either cutting or cauterizing current to a resectoscope. However, this patent is not in anyway concerned with a resectoscope adaptable for either manual or automatic operation, or a resectoscope wherein heating current is automatically timed with the reciprocating stroke of a cutting element to intermittently apply heat to the cutting tip during its cutting stroke.
U.S. Pat. No. 3,763,864, issued to Dremann, relates to an automatically powered, cold-punch resectoscope wherein the cutting tip is automatically reciprocated through the use of a hydraulic circuit. The Dremann device does not employ any heating means for energizing the cutting tip in view of the fact that the invention is directed to a cold-punch resectoscope. Moreover, there is no mechanism provided for converting the resectoscope from automatic to manual operation. In other words, like the Wallace device disclosed in earlier-referenced Canadian Pat. No. 452,125, the Dremann device either operates automatically under the control of the hydraulic circuit, or it does not operate at all.